Mixer drum drive with variable displacement motor

A drum drive system for a vehicle, the drum drive system comprising:

• a non-transitory computer-readable storage medium having instructions stored thereon that, upon execution by one or more processors, cause the one or more processors to:
• operate a prime mover, a variable displacement pump mechanically coupled to the prime mover, and a variable displacement motor fluidly coupled to the variable displacement pump to drive a drum of the vehicle;
• acquire pressure data indicative of a pressure of a fluid flowing between the variable displacement pump and the variable displacement motor;
• and
• in response to the pressure of the fluid being below a threshold pressure and while maintaining a drum speed of the drum:
• increase a pump displacement of the variable displacement pump;
• reduce a speed of the prime mover;
• and
• reduce a motor displacement of the variable displacement motor.

A drum drive system for a vehicle, the drum drive system comprising:

• a controller configured to control a prime mover, a variable displacement pump, and a variable displacement motor of the vehicle to provide a target drum speed for a drum of the vehicle, wherein, to provide the target drum speed and when the target drum speed is below a drum speed threshold, the controller has programmed instructions to:
• operate the variable displacement motor at a maximum motor displacement;
• operate the prime mover at a low speed;
• and
• operate the variable displacement pump at a pump displacement that provides the target drum speed.